The effect of long-term exercise on the secretion of serum Ghrelin in obese men

Ghrelin, a 28-amino acid peptide, plays an important role in weight regulation and energy homeostasis. In this study, Ghrelin responses to a long-term aerobic exercise in obese men was studied. In this semi-experimental study, thirty adult obese males were randomly divided into a physically active (experimental) or a physically inactive (control) groups. Serum Ghrelin, lipid profile (TG, TC, LDL, HDL) and anthropometrical indexes were measured respectively before and after a 12 week aerobic exercise and detraining in the experimental and control groups. Blood samples were taken from all participants after an overnight fasting (12 hours). Statistical analysis was performed by means of SPSS software (version 15) using T-test method. Aerobic exercise led to a significant decrease in serum Ghrelin and all anthropometrical indexes in the experimental group (P<0.05). In addition, TG concentration and ratio of TG to HDL decreased after aerobic exercise in the experimental group (P<0.05). All variables remained constant in the control group after detraining. The findings of the present study show that an exercise program, while significantly decreasing serum Ghrelin level, can be followed by weight loss and a decrease in fat tissues in obese men.